Bitumen is a highly viscous form of petroleum which is widely produced in the oil and gas industry. Large natural deposits of bitumen may be found, for example, in Canadian oil sands. The high viscosity of bitumen is at least partly due to the asphaltene content of bitumen, which can complicate the recovery and transportation of bitumen to refineries. Increasing energy demands worldwide mean that accessible heavy or viscous oils, such as bitumen, will become increasingly important sources of energy moving forward, despite the challenges associated with recovery and transportation.
Currently, it is common to transport bitumen from recovery sites to refineries via railway. In some examples, asphaltenes may be removed from the bitumen thereby reducing the viscosity of the bitumen. The asphaltenes may then be transported via railway, while the remainder of the recovered bitumen is transported via pipeline. In either case, the costs associated with railway transport can be substantial.
Recovered bitumen may alternatively be transported via pipelines. However, the high viscosity of bitumen presents challenges for pipeline transportation infrastructure. Traditional approaches to the pipeline transport of bitumen include heating, dilution, oil-in-water systems, core annular flow, and partial upgrading (Saniere et al. (2004) Pipeline Transportation of Heavy Oils, a Strategic, Economic, and Technological Challenge; Oil & Gas Science and Technology, 59 (5), 455-466). One of the main approaches for bitumen transport via pipeline is dilution, which involves diluting bitumen with a diluent such as “Pentane Plus” in order to generate a blend with decreased viscosity allowing for transport via pipeline. The diluent may be recovered and recycled, or the diluent/bitumen blend may be sold or used directly. In either case, large amounts of diluent may be required, which can incur substantial added expense.
Alternative bitumen processing and transportation methods are being developed. One example is provided in WO2012/050649, which describes forming coated asphaltene particles, slurrying the coated asphaltene particles with the carrier, and transporting the slurry to a treatment facility. However, cost-effective generation of coated asphaltene particles, which must be sufficiently stable in the carrier, remains a significant challenge. The difficulty of bitumen transport in pipelines remains substantial due to the asphaltene component of bitumen, and improved methods for asphaltene processing and transport are desirable. It would therefore be desirable to provide methods of pipeline-based bitumen transport which do not rely on the use of large diluent volumes. Methods for transporting bitumen via pipeline are highly sought-after in the oil and gas industry.